Method and system for varying the gage of metal strips

Abstract

A variable thickness process and system for processing steel strips to obtain a profile with at least two different thicknesses along its width which includes at least one heating step, and at least one stretching step and one straightening step.

1 . A method for varying the gage of a metal strip, comprising:
 heating a section of the strip;   forming the heated section using a set of stretch forming rolls;   flattening the strip using a set of straightening rolls; and   repeat stretching and flattening steps until achieving the required gage reduction in specific areas of the strip.   
     
     
         2 . The method for varying the gage of a metal strip in accordance with  claim 1 , wherein the method comprises heating means which might be induction heating means. 
     
     
         3 . The method for varying the gage of a metal strip in accordance with  claim 1 , wherein the metal strip might be made primarily of steel such as boron steel. 
     
     
         4 . The method for varying the gage of a metal strip in accordance with  claim 1 , wherein between heating and stretching steps, there could be an optional flattening step of the strip by straightening rolls. 
     
     
         5 . A system for varying the gage of a metal strip, the system comprising:
 heating means to punctually increase the temperature of a steel strip at specific at least one specific section;   a first set of stretch forming rolls for stretching a section of the strip so as to form a slightly convex shape in the heated section, the first stretch forming rolls are one adjacent to the other in order for at least one of them to be able to exert pressure to the steel strip;   a couple of first straightening rolls for flattening the prior deformations of the strip, the first straightening rolls being adjacent one to the other so both are able to exert pressure on the steel strip as the steel strip passes in between both rollers;   subsequent pairs of stretch forming rolls and straightening rolls as required to achieve the desired thickness of the heated section.   
     
     
         6 . The system for varying the gage of a metal strip in accordance with  claim 5 , wherein before first stretch forming rolls, there could be an optional pair of straightening rolls for flattening the preexistent deformations of the strip. 
     
     
         7 . The system for varying the gage of a metal strip in accordance with  claim 5 , wherein heating means may refer to an induction heating device. 
     
     
         8 . The system for varying the gage of a metal strip in accordance with  claim 7 , wherein the metal strip might be made of steel such as boron steel.